How much caffeine is in your cup?

Feeling jittery? Before you order your next pumpkin spice latte, consider how much caffeine you're consuming. While caffeine has its perks, boosting alertness and concentration, too much can cause stomach upset, insomnia, anxiety, muscle tremors and rapid heartbeat, reports MedlinePlus. Caffeine isn’t limited to drinks, either — it shows up in everything from ice cream to headache medicine.